Method of increasing mass transfer rate of acid gas scrubbing solvents

ABSTRACT

A method and catalysts for increasing the overall mass transfer rate of acid gas scrubbing solids is disclosed. Various catalyst compounds for that purpose are also disclosed.

This document claims priority of U.S. Provisional Patent ApplicationSer. No. 61/925,693, filed on Jan. 10, 2014, the full disclosure ofwhich is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to various methods and catalystsfor increasing the overall mass transfer rate of acid gas scrubbingsolvents utilizing various catalyst compounds.

BACKGROUND

The cleanup of acid gasses or sour gas, such as CO₂ in particular, fromnatural gas and in oil refining has been an extensively practicedtechnology. The industrial removal of CO₂ from natural gas dates back tothe 1930's. In the 21^(st) century, due to the potential impact ofanthropogenic CO₂ emissions on the climate, post-combustion CO₂ capturehas gained tremendous attention. While several technologies exist forthe removal of acid gasses one of the most commonly employed practicesis the use of aqueous amines. Of these amines, tertiary amines are oftenused for natural gas applications due to their low energy ofregeneration. For post-combustion CO₂ capture applications primary andsecondary amines tend to be in part favored by their faster rate at thelow gaseous CO₂ concentration condition. Regardless of the application,the mass transfer rate in the absorber column dictates the size of thecolumn (capital cost) used and, consequently, has a substantial impacton the overall process cost. A simplified process depicting a thermalswing process is presented in FIG. 1. An aqueous amine solution iscirculated between the absorber 10 and stripper 12. The gas, containingCO₂, enters the bottom of the absorber where it contacts the aqueousamine absorbent removing it from the gas stream. The liquid solution,CO₂ rich amine solution, is then passed through a heat exchanger 14 toimprove efficiency before being heated to a higher temperature in thestripper 12. The stripper 12 removes the CO₂ as a gas from the aminesolution to produce a lean, or CO₂ deficient solution. The lean solutionis returned to the absorber 10 by way of the heat exchanger 14 to repeatthe process.

In order to minimize system capital (absorber cost) it is important tomaximize the overall mass transfer rate for the scrubber system as thereis a direct correlation between the two. This invention relates tomethods for this purpose as well as to catalyst compounds useful inthose methods.

SUMMARY

A method is provided for increasing the overall mass transfer rate ofacid gas scrubbing solvents. The method comprises adding a catalystcompound to a fluid stream including an acid gas and an acid gasscrubbing solvent wherein that catalyst compound has a chemical formula:

where:

(a) M is any group VII B through XII B element;

(b) x=neutral sigma donor or monovalent anion;

(c)

where R₁=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl, Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻

R₂=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₃=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₄=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₅=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₆=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₇=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₈=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻; and

-   -   [CH₂Q]⁺[A]⁻=

where A=monovalent anion: Cl, Br, I, F, PF₆, BF₄, acetate,trifluoroacetate, ClO₄, NO₃, and

Q=monovalent cation: PR₃, R=alkyl, cyclic alkyl, Aryl, O-alkyl, O-Aryl

NR₃, R=alkyl, cyclic alkyl, N-heterocyclic ring, imidazole; and

(d)

where

-   -   E₁=N, P, S, B    -   E₂=N, P, S, O, B    -   n=1-10.

In an alternative embodiment, the method comprises adding a catalystcompound to a fluid stream including an acid gas and an acid gasscrubbing solvent wherein that catalyst compound has a chemical formula:

where:

M is any group VII B through XII B element;

(b) x=neutral sigma donor or monovalent anion;

(c)

where R₁=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl, Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻

R₂=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₃=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₄=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₅=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₆=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₇=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₈=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻; and

-   -   [CH₂Q]⁺[A]⁻=

where A=monovalent anion: Cl, Br, I, F, PF₆, BF₄, acetate,trifluoroacetate, ClO₄, NO₃, and

Q=monovalent cation: PR₃, R=alkyl, cyclic alkyl, Aryl, O-alkyl, O-ArylNR₃, R=alkyl, cyclic alkyl, N-heterocyclic ring, imidazole

(d)

where

-   -   E₁=N, P, S, B    -   E₂=N, P, S, O, B    -   n=1-10.

In yet another embodiment, the method comprises adding a catalystcompound to a fluid stream including an acid gas and an acid gasscrubbing solvent wherein that catalyst compound has a chemical formula:

where:

(a) M is any group VII B through XII B element;

(b) x=neutral sigma donor or monovalent anion; and

(c)

R₁=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units);OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃, [CH₂Q]+[A]-; and

-   -   [CH₂Q]+[A]-=        where A=monovalent anion: Cl, Br, I, F, PF₆, BF₄, acetate,        trifluoroacetate, ClO₄, NO₃, and Q=monovalent cation: PR₃,        R=alkyl, cyclic alkyl, Aryl, O-alkyl, O-Aryl NR₃, R=alkyl,        cyclic alkyl, N-heterocyclic ring, imidazole        R₂=CE; where C=any alkyl, cyclic alkyl, aryl, and E=OH, NH₂,        NR₃, R=alkyl, cyclic alkyl, N-heterocyclic ring, imidazole,        morpholine.

In one possible embodiment, the catalysts compound has a chemicalformula:

In one possible embodiment, the catalysts compound has a chemicalformula:

In one possible embodiment, the catalysts compound has a chemicalformula:

In one possible embodiment, the catalysts compound has a chemicalformula:

In one possible embodiment, the catalysts compound has a chemicalformula:

In one possible embodiment, the catalysts compound has a chemicalformula:

In one possible embodiment, the catalysts compound has a chemicalformula:

In one possible embodiment, the catalysts compound has a chemicalformula:

In one possible embodiment, the catalysts compound has a chemicalformula:

In one possible embodiment, the catalysts compound has a chemicalformula:

In any of the embodiments, the neutral sigma donor or monovalent anionmay be selected from a group consisting of H₂O, Cl, Br, F, I, acetate,triflate, perchlorate, nitro, pyridine, ethanol, methanol,tetrahydrofuran, dimethylsulfoxide, carbonate, bicarbonate, sulfate,nitrate and nitrite.

In any of the embodiments, the acid gas scrubbing solvent includes anamine or a mixture of amines, and/or no-amine based solvent such asalkali carbonate/bicarbonate solution. In one possible embodiment theacid gas scrubbing solvent includes a mixture of (a) a promoter amineand (b) a tertiary amine.

In one possible embodiment, the acid gas scrubbing solvent includeschemical compounds selected from a group including but not limited to,monoethanolamine (MEA), 1-amino-2-propanol (1A2P), 3-amino-1-propanol,2-amino-1-propanol, 2-amino-1-butanol, 1-amino-2-butanol,3-amino-2-butanol, 2-(methylamino)ethanonol (MAE),2-(ethylamino)ethanol, morpholine, piperazine (PZ), 1-methylpiperazine(NMP), 2-methylpiperazine, hydroxypiperadine, 2-piperidineethanol,N-aminoethylpierazine (AEP), aminopropylmorpholine, 4-aminopiperidine,2-amino-2-methyl-1-propanol (AMP), diethanolamine (DEA),diisopropanolamine (DIPA), glycine, alanine, β-alannine, sarcosine,ethylene diamine (EDA), 1,3-propanediamine, 1,4-butanediamine,1,5-pentanediamine, 1,6-hexanediamine, methyldiethanolamine (MDEA),triethanolamine (TEA), dimethylethanolamine (DMEA),N,N,N′,N′-tetramethyl-1,8-naphthalenediamine, diethylmonoethanolamine,dipropylmonoethanolamine, 1,4-dimethylpiperazine, NN,N′,N′-tetramethyl-1,6-hexanediamine,N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine,N,N,N′,N′,N″-pentamethyldiethylenetriamine,N,N,N′,N′-tetramethylethylenediamine,N,N,N′,N′-tetramethylpropane-1,3-diamine,N,N,N′,N′-tetramethylbutane-1,4-diamine,N,N,N′,N′-tetramethyl-1,5-pentanediamine, alkali carbonate, and mixturesthereof.

Further the catalyst compound is provided at a concentration of betweenabout 0.05 mM and about 100 mM.

Various catalyst compounds are also claimed.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The accompanying drawings incorporated herein and forming a part of thespecification, illustrate several aspects of the present method andtogether with the description serve to explain certain principlesthereof. In the drawings:

FIG. 1 is a schematical illustration of a process for removing acid gasfrom a fluid stream utilizing solvent and thermal swing regeneration.

FIG. 2 is a plot of mass transfer coefficients versus carbon loadingfrom WWC testing of 30 wt % MEA and 30 wt % MEA with 2 mM CAER-C3P at40° C.

DETAILED DESCRIPTION

This document relates generally to methods and catalysts for increasingoverall mass transfer rate of acid gas scrubbing solvents as well as tonovel transition metal monomer complexes incorporating a singletransition metal atom.

The method may be broadly described as comprising adding a catalystcompound to a fluid stream including an acid gas and an acid gasscrubbing solvent. The catalyst compound has a chemical formula:

where:

(b) M is any group VII B through XII B element;

(b) x=neutral sigma donor or monovalent anion;

(c)

where R₁=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl, Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻

R₂=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₃=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₄=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₅=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₆=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₇=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₈=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻; and

-   -   [CH₂Q]⁺[A]⁻=

where A=monovalent anion: Cl, Br, I, F, PF₆, BF₄, acetate,trifluoroacetate, ClO₄, NO₃, and

Q=monovalent cation: PR₃, R=alkyl, cyclic alkyl, Aryl, O-alkyl, O-Aryl

NR₃, R=alkyl, cyclic alkyl, N-heterocyclic ring, imidazole; and

(d)

where

-   -   E₁=N, P, S, B    -   E₂=N, P, S, 0, B    -   n=1-10.

Specific catalyst compounds useful in this method include, but are notlimited to the following:

In another possible embodiment, the method may be broadly described ascomprising adding a catalyst compound to a fluid stream including anacid gas and an acid gas scrubbing solvent. The catalyst compound has achemical formula:

where:

(a) M is any group VII B through XII B element;

(b) x=neutral sigma donor or monovalent anion;

(c)

where R₁=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl, Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻

R₂=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₃=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₄=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₅=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₆=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₇=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻

R₈=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]⁺[A]⁻; and

-   -   [CH₂Q]⁺[A]⁻=

where A=monovalent anion: Cl, Br, I, F, PF₆, BF₄, acetate,trifluoroacetate, ClO₄, NO₃, and

Q=monovalent cation: PR₃, R=alkyl, cyclic alkyl, Aryl, O-alkyl, O-Aryl

NR₃, R=alkyl, cyclic alkyl, N-heterocyclic ring, imidazole

(d)

where

-   -   E₁=N, P, S, B    -   E₂=N, P, S, O, B    -   n=1-10.

Specific catalyst compounds useful in this embodiment of the methodinclude, but are not limited to the following:

Still further, the method relates to a more efficient removal of carbondioxide from a gaseous stream containing carbon dioxide and/or otheracidic gases. In particular, the method separates carbon dioxide from agas mixture using a combination of a homogeneous CO₂ hydration catalystin the presence of an amine(s) and/or ionic carbonate/bicarbonate. Thecombination of catalyst and amine(s) and/or chemicals provides anoverall increase in mass transfer rate resulting in either 1) lowercapital cost for CCS due to smaller absorber tower, or 2) reduced energycost in the stripper from obtaining a more carbon rich solution. Thecatalysts have the ability to react with CO₂ in the gas stream to formbicarbonate which reacts with the amine(s) to form an ammoniumbicarbonate or carbamate where the CO₂ is now considered absorbed.

It was originally believed that CO₂ hydration catalyst required a4-coordinate ligand in order to stabilize the metal center and show CO₂hydration activity under carbon capture conditions. However, recentresults obtained at the CAER show that catalysts containing 2-coordinate(bidentate) ligands of the general structure

are capable of increasing the overall mass transfer of carbon capture byaqueous capture solutions. A recent catalyst identified by the CAER

This catalyst contains a 2-coordainate, bidentate moiety from the ligandwhile monovalent anions occupy the other coordination sites.

Without limiting the scope of the method, a possible example of thesystem would consist of 0.001-0.1 wt % of catalyst containing abidentate ligand and more than 20 wt % of amine(s), ethanolamine (MEA),methylydiethanolamine (MDEA), triethanolamine (TEA),dimethylethanolamine (DMEA), 1-amino-2-propanol (1A2P),2-amino-1-propanol (1A2P), 3-aminopropanol, sodium ion, potassium ion,or combinations thereof, for examples.

Addition of catalyst CAER-C3P (2 mM) to a 30% ethanolamine solutionresulted in a ˜25% increase in mass transfer rate over the working rangeof the solvent (see FIG. 2). As shown in FIG. 2, a greater enhancementin mass transfer is observed at higher carbon loadings (C/N>0.4, whereC/N is the ratio of moles of carbon in solution compared to the moles ofamine). This suggests that the rate of the catalyst is on the order of10⁵ M⁻¹ s⁻¹, two orders of magnitude higher than previousstate-of-the-art catalyst, [Zn(cyclen)(H₂O)]²⁺. Primary amines reactvery rapidly with CO₂ and in order for a catalyst to contribute to theoverall mass transfer second order rate constants must of the magnitudeof 10⁵ M⁻¹ s⁻¹. This is the first example of catalysts containing a2-coordinate, bidentate ligand showing activity in concentrated primaryamine solutions.

The success of catalyst CAER-C3P in increasing overall mass transferrates in 30 wt % MEA opened a new and novel area for catalystdevelopment towards carbon capture purposes. Based on these results wedeveloped a new family of CO₂ hydration catalysts that are lesssynthetically demanding than previous catalysts and thus more costeffective. That new catalyst family is schematically illustrated below.

In another possible embodiment, the method may be broadly described ascomprising adding a catalyst compound to a fluid stream including anacid gas and an acid gas scrubbing solvent. The catalyst compound has achemical formula:

where:

(a) M is any group VII B through XII B element;

(b) x=neutral sigma donor or monovalent anion; and

(c)

For any of the embodiments, the neutral sigma donor or monovalent anionmay be selected from a group consisting of H₂O, Cl, Br, F, I, acetate,triflate, perchlorate, nitro, pyridine, ethanol, methanol,tetrahydrofuran, dimethylsulfoxide, carbonate, bicarbonate, sulfate,nitrate and nitrite.

For any of the method embodiments the acid gas scrubbing solvent mayinclude an amine. In one possible embodiment the acid gas scrubbingsolvent includes a mixture of (a) a promoter amine, selected from agroup of primary and secondary amines, and (b) a tertiary amine, and/or(c) non-amine chemical compounds.

Such a mixture is described in detail in copending U.S. patentapplication Ser. No. 13/853,186, filed on Mar. 29, 2013 and entitled“Solvent and Method for Removal of an Acid Gas from a Fluid Stream”, thefull disclosure of which is incorporated herein by reference. Promoteramines useful in the present method include, but are not limited to, theprimary and secondary amines such as 3-N-sulfonylamine (SA),3-aminopropionitrile (APN), diethyl 2-aminoethanephosphonate (EtP2),N-methyltetrahydrothiophen-3-amine 1,1-dioxide,2,2′-sulfonyldiethanamine, 3,3′-sulfonyldipropaneamine,4,4′-sulfonyldibutanenamine, 2-aminoethyl methyl sulfone,4-aminobutanenitrile, 6-aminohexanenitrile,3-(methylamino)propanenitrile, diethyl[2-(methylamino)ethyl]phosphonate,diethyl(3-aminopropyl)phosphonate, diethyl (4-aminobutyl)phosphonate,diethyl (5-aminopentyl)phosphonate, diethyl (6-aminohexyl)phosphonate,2-(tert-butoxy)ethan-1-amine,N-methyl-2-[(2-methyl-2-propanyl)oxy]ethanamine and mixtures thereof.

Tertiary amines and carbonate based salts useful in the present methodinclude but are not limited to methyldiethanolamine (MDEA),triethanolamine (TEA), N,N,-dialkylethanolamine,N,N,N′,N′-tetraalkyl-1,8-naphthalenediamine, N,N,-dialkylbenzylamine,1,4-dialkylpiperazine, N,N,N′,N′-tetraalkyl-1,6-hexanediamine,N,N,N′,N′-tetraalkyl-1,5-pentanediamine,N,N,N′,N′-tetraalkyl-1,4-butanediamine,N,N,N′,N′-tetraalkyl-1,3-propanediamine,N,N,N′,N′-tetraalkyl-1,2-ethanediamine,N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine,N,N,N′,N′,N″-pentaalkyldiethylenetriamine,N,N,N′,N′,N″-pentaalkyldipropylaminetriamine,N,N,-dialkylcyclohexylamine, N,N,N′,N′-tetraalkylbis(aminoethyl)ether,N,N,-dimethyl-2(2-aminoethoxy)ethanol, alkali carbonates where alkylrepresents any methyl, ethyl, propyl, butyl isomer, and mixturesthereof. In one possible embodiment, the catalyst compound is providedin the fluid stream with a concentration of between about 0.05 mM andabout 50 mM. In another possible embodiment the catalyst compound isprovided in the fluid stream with a concentration of between 50.1 mM and75 mM. In yet another possible embodiment, the catalyst compound isprovided in the fluid stream with a concentration of between about 75.1mM and 100 mM.

Primary and secondary amines useful in the present method include butare not limited to monoethanolamine (MEA), 1-amino-2-propanol (1A2P),3-amino-1-propanol, 2-amino-1-propanol, 2-amino-1-butanol,3-amino-2-butanol, 1-amino-2-butanol, 2-(alkylamino)ethanonol (MAE),diglycolamine, morpholine, piperazine (PZ), 1-methylpiperazine (NMP),2-methylpiperazine, hydroxypiperadine, hydroxymethylpiperazine,2-piperidineethanol, N-aminoethylpierazine (AEP), aminopropylmorpholine,4-aminopiperidine, 3-aminopiperidine, 2-amino-piperidine,diethanolamine, 2-amino-2-methyl-1-propanol (AMP), diethanolamine (DEA),diisopropanolamine (DIPA), glycine, alanine, β-alanine, sarcosine,isopropanolamine, benzylamine, ethylene diamine (EDA),1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine,1,6-hexanediamine.

In any of the embodiments, the catalyst compound must be stable underthe relatively high temperature conditions (e.g. between perhaps 70 and170° C.) found within the stripper 12. The present catalyst compoundsmeet this requirement.

The following examples further illustrate how to synthesize ormanufacture certain representative catalysts used in the method ofincreasing the overall mass transfer rate of acid gas scrubbingsolvents.

Example 1

Preparation of (H₂L7)[CL]: A 100 mL round bottom flask was charged with30 mL EtOH and 1-(3-Formyl-4-hydroxybenzyl)-3-triphenylphosphoniumchloride (4.334 g, 10.03 mmol). An ethanolic solution of2-Amino-2-methyl propanol (0.912 g 10.24 mmol) was added drop wise tothe solution. The mixture was heated at reflux for two hours. Thesolvent was removed under vacuum to give yellow solids. The yellowsolids were washed with ethanol (3×15 mL) and diethyl ether (3×15 mL)and collected via filtration (4.425 g, 78%).

Preparation of CAER-C7z: A 100-mL round-bottom flask was charged with(H₂L7)[Cl] (5.043 g, 10.01 mmol) and EtOH (30 mL) was added to make acolorless slurry. Triethyl amine 3.2 mL (23.023 mmol) was added slowlyunder vigorous stirring. An ethanolic solution of ZnCl₂ (1.632 g, 12.0mmol, 5 mL) was added drop wise to the mixture. The mixture was heatedat reflux for two hours. The solution was cooled to 25° C. and a paleyellow solid precipitated out of solution. The pale yellow solid wascollected by filtration and washed with ethanol (3×15 mL) and diethylether (3×15 mL) to give the desired product (4.852 g, 85%).

Example 2

Preparation of (H₂L8)[CL]: A 100 mL round bottom flask was charged withEtOH (30 mL) and 1-(3-Formyl-4-hydroxybenzyl)-3-triphenylphosphoniumchloride (4.327 g, 10.01 mmol). An ethanolic solution ofmonoethanolamine (0.9 mL, 15.01 mmol, 5 mL) was added drop wise to thesolution and the mixture was heated at reflux for two hours. The solventwas removed under reduced pressure to give a yellow residue. Diethylether was added to the reaction vessel and stirred overnight to give ayellow powder which was collected via filtration and washed with diethylether (3×30 mL) (4.452 g, 93%).

Preparation of CAER-C8z: A 100-mL round-bottom flask was charged with(H₂L8)[Cl] (4.812 g, 10.12 mmol) and EtOH (30 mL) was added to make aclear solution. Triethylamine (3.2 mL, 23.023 mmol) was added slowlywhile stirring. An ethanolic solution of ZnCl₂ (1.687 g, 12.35 mmol, 5mL)) was added drop wise to the mixture. The mixture was heated atreflux for two hours. The mixture was cooled to 25° C. and a pale yellowsolid was collected via filtration and washed with ethanol (3×15 mL)then diethyl ether (3×15 mL) to give the desired product (4.688 g, 86%).

Example 3

Preparation H₂L9: A 100-mL round-bottom flask was chargedsalicylaldehyde (1.95 mL, 16.5 mmol) and EtOH (10 mL) to make a clearsolution. Ethanolamine (1 mL, 16.6 mmol) was added dropwise to the abovesolution with continuous stifling. The solution was stirred at roomtemperature (25° C.) for one hour and the solvent was removed undervacuum to give the product as a viscous, yellow-orange oil (2.219 g,81%).

Preparation of CAER-C9z: A 100-mL round-bottom flask was charged withH₂L9 (1.656 g, 10.01 mmol) and EtOH (30 mL) to make a clear solution.Triethylamine (3.2 mL, 23.0 mmol) was added while stifling. An ethanolicsolution of ZnCl₂ (1.687 g, 12.35 mmol, 5 mL) was added dropwise to themixture. The mixture was heated at reflux for two hours. The mixture wascooled to 25° C. and a pale yellow solid was collected via filtrationand washed with ethanol (3×15 mL) then diethyl ether (3×15 mL) to givethe desired product (2.199 g, 80%).

Example 4

Preparation of H₂L10: A 100-mL round-bottom flask was chargedsalicylaldehyde (3 mL, 28.3 mmol) and EtOH (10 mL) to make a clearsolution. 2-Amino-2-methyl-1-propanol (2.6775 g, 16.6 mmol) was added tothe above solution with continuous stirring. The solution was stirred atroom temperature for one hour and the solvent was removed under vacuumto give a yellow residue. The yellow residue was dissolved indichloromethane (5 mL) and n-pentane was added (20 mL) to produce ayellow powder. The yellow powder was collected via filtration and washedwith ether (3×15 mL) to give the desired product (4.767 g, 87%).

Preparation of CAER-C10z: A 100-mL round-bottom flask was charged withH₂L10 (1.933, 10.0 mmol) and EtOH (30 mL) to make a clear solution.Triethylamine (3.2 mL, 23 mmol) of was added while stifling. Anethanolic solution of ZnCl₂ (1.687 g, 12.35 mmol) was added dropwise tothe mixture. The mixture was stirred for 48 hr at room temperature (25°C.). The solvent was reduced under vacuum to 5 mL and acetonitrile wasadded to the solution to give a pale yellow powder. The pale yellowsolid was collected via filtration and washed with acetonitrile (3×15mL) then diethyl ether (3×15 mL) to give the desired product (2.456 g,81%).

Example 5

Preparation of H₂L11: A 100-mL round-bottom flask was chargedsalicylaldehyde (2.7 mL, 25 mmol) and EtOH (10 mL) to make a clearsolution. 2-methoxyethylamine (2 mL, 23 mmol) was added to the solutionwith continuous stirring. The solution was stirred at room temperaturefor two hour and the solvent was removed under reduced vacuum to givethe desired product as a dark yellow-orange, viscous liquid (3.769 g,83%).

Preparation of CAER-C11z: A 100-mL round-bottom flask was charged withH₂L11 (1.793, 10.01 mmol) and EtOH (30 mL) to make a clear solution.Triethylamine (3.2 mL, 23 mmol) was added while stifling. An ethanolicsolution of ZnCl₂ (1.687 g, 12.35 mmol, 5 mL) was added dropwise to themixture. The mixture was heated at reflux for 3 hours. The solvent wasremoved under reduced pressure to give a yellow oil. Diethyl ether wasadded to the oil to give a yellow powder which was collected viafiltration. The yellow powder was washed with diethyl ether (3×15 mL) togive the desired product (2.444 g, 85%).

Example 6

Preparation of H₂L12: A 100-mL round-bottom flask was chargedsalicylaldehyde (2.06 mL, 19.5 mmol) and EtOH (10 mL) to make a clearsolution. 4-(Aminomethyl)piperidine (2.0256 g, 17.8 mmol) was added tothe solution with continuous stirring. The solution was stirred at roomtemperature for two hours at which point the solvent was removed underreduced pressure to give the desired product as a yellow power (3.521 g,87%).

Preparation of CAER-C12z: A 100-mL round-bottom flask was charged withH₂L12 (2.19, 10.0 mmol) and acetonitrile (30 mL) to make a clearsolution. Triethylamine (3.2 mL, 23.023 mmol) was added while stirring.An acetonitrile solution of ZnCl₂ (1.776 g, 12.50 mmol) was addeddropwise to the mixture. The mixture was stirred at room temperature(25° C.) for 3 hours at which point a yellow powder was generated. Theyellow powder was collected via filtration and washed with acetonitrile(3×15 mL) and diethyl ether (3×15 mL) to give the desired product (2.668g, 83%).

Example 7

Preparation of (H₂L13)[CL]: A 100 mL round bottom flask was charged withEtOH (30 mL) and 5-(1-methylimidazolemethyl)-2-hydroxybenzaldehydechloride (2.528 g, 10.0 mmol). An ethanolic solution of 2-Amino-2-methylpropanol (0.912 g 10.24 mmol) was added drop wise to the solution. Themixture was heated at reflux for two hours. The solvent was removedunder reduced pressure to give a yellow powder which was collected viafiltration and washed with ethanol (3×15 mL) and diethyl ether (3×15 mL)to give the desired product (2.872 g, 89%).

Preparation of CAER-C13z: A 100-mL round-bottom flask was charged with(H₂L13)[Cl] (3.238 g, 10.01 mmol) and EtOH (30 mL) to make a clearsolution. Triethylamine (3.2 mL, 23.023 mmol) was added while stifling.An ethanolic solution of ZnCl₂ (1.687 g, 12.35 mmol) was added dropwiseto the mixture. The mixture was heated at reflux for two hours at whichpoint a yellow powder was produced which was collected via filtrationand washed with ethanol (3×15 mL) then diethyl ether (3×15 mL) to givethe desired product (3.123 g, 81%).

Example 8

Preparation of (H₂L7)[BF₄]: A 100 mL round bottom flask was charged EtOH(30 mL) and 5-(triphenylphosphine-methyl)-2-hydroxybenzaldehydetetrafluoroborate (4.842 g, 10.0 mmol) of. An ethanolic solution of2-Amino-2-methyl propanol (0.912 g 10.2 mmol) was added drop wise to thesolution. The mixture was heated at reflux for two hours. The solventwas removed under reduced pressure to give a yellow residue. Diethylether was added to the reaction vessel and stirred overnight to give ayellow powder which was collected via filtration and washed with diethylether (3×15 mL) to give the desired product (4.956 g, 89%).

Preparation of CAER-C14z: A 100-mL round-bottom flask was charged with(H₂L7)[BF₄] (1.1108 g, 2.002 mmol) and MeOH (30 mL) to make a colorlessslurry. Triethylamine (0.332 mL, 2.30 mmol) was added to the stirredmixture. An ethanolic solution of ZnBF₄ (0.2868 g, 1.12 mmol, 5 mL) wasadded dropwise to the mixture. The mixture was heated at reflux for twohours. The solution mixture was cooled to room temperature (25° C.) togive a yellow powder which was collected via filtration and washed withethanol (3×15 mL) and diethyl ether (3×15 mL) to give the desiredproduct (1.011 g, 86%).

Example 9

Preparation of CAER-C15z: A 100-mL round-bottom flask was charged withH₂L9 (1.986 g, 12.02 mmol) and EtOH (15 mL) to make a clear solution.Triethylamine (1.95 mL, 13.8 mmol was added while stirring. An ethanolicsolution of ZnCl₂ (1.804 g, 13.2 mmol, 5 mL) was added dropwise to themixture. The mixture was heated at reflux for two hours to give a brightyellow powder which was collected via filtration and washed with ethanol(3×15 mL) then diethyl ether (3×15 mL) to give the desired product(1.8449 g, 62%).

Example 10

Preparation of CAER-C16z: A 100-mL round-bottom flask was charged withH₂L10 (5.500 g, 28.5 mmol) and EtOH (20 mL) to make a clear solution.Triethylamine (7.93 mL, 57.0 mmol) was added while stifling. Anethanolic solution of ZnCl₂ (4.264 g, 30.8 mmol, 5 mL) was addeddropwise to the mixture. The mixture was stirred at room temperature(25° C.) for 48 hr. The solvent was removed under reduced pressure togive a yellow residue and acetonitrile was added to give a yellow powderwhich was collected via filtration and washed with acetonitrile (3×15mL) then diethyl ether (3×15 mL) to give the desired product (4.1758 g,51%).

Example 11

Preparation of CAER-C3p: To a 100-mL round-bottom flask was added[H2LP]Cl2 (5.002 g, 5.63 mmol), EtOH (40 mL), and triethylamine (1.75mL, 12.0 mmol) was added to give a clear yellow solution. Zinc chloride(1.363 g, 10.00 mmol) dissolved in EtOH (10 mL) was added, producing apale yellow slurry. The reaction flask was immersed in a silicon fluidbath at 85° C. and was stirred for 3 h, producing a pale yellowprecipitate which was collected via filtration through a medium porosityglass fritted funnel. The pale yellow powder was washed with EtOH thenether (3×20 mL) and air dried to give the desired product (5.679 g,93%).

The foregoing has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theembodiments to the precise form disclosed. Obvious modifications andvariations are possible in light of the above teachings. All suchmodifications and variations are within the scope of the appended claimswhen interpreted in accordance with the breadth to which they arefairly, legally and equitably entitled.

What is claimed:
 1. A method of increasing overall mass transfer rate ofacid gas scrubbing solvents, comprising: adding a catalyst compound to afluid stream including an acid gas and an acid gas scrubbing solvent,said catalyst compound having a chemical formula:

where: (c) M is any group VII B through XII B element; (b) x=neutralsigma donor or monovalent anion; (c)

where R₁=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl, Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₂=H, any alkyl, RCOOH (R=alkylranging from 0-10 carbons); OligoPEG, phosphate, ROH (R=alkyl rangingfrom 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃;NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₃=H, anyalkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG, phosphate,ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeatunits); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃,[CH₂Q]⁺[A]⁻ R₄=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₅=H, any alkyl, RCOOH (R=alkylranging from 0-10 carbons); OligoPEG, phosphate, ROH (R=alkyl rangingfrom 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃;NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₆=H, anyalkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG, phosphate,ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeatunits); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃,[CH₂Q]⁺[A]⁻ R₇=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₈=H, any alkyl, RCOOH (R=alkylranging from 0-10 carbons); OligoPEG, phosphate, ROH (R=alkyl rangingfrom 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃;NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻; and[CH₂Q]⁺[A⁻]=

where A=monovalent anion: Cl, Br, I, F, PF₆, BF₄, acetate,trifluoroacetate, ClO₄, NO₃, and Q=monovalent cation: PR₃, R=alkyl,cyclic alkyl, Aryl, O-alkyl, O-Aryl NR₃, R=alkyl, cyclic alkyl,N-heterocyclic ring, imidazole; and (d)

where E₁=N, P, S, B E₂=N, P, S, O, B n=1-10.
 2. The method of claim 1,wherein said neutral sigma donor or monovalent anion is selected from agroup consisting of H₂O, Cl, Br, F, I, acetate, triflate, perchlorate,nitro, pyridine, ethanol, methanol, tetrahydrofuran, dimethylsulfoxide,carbonate, bicarbonate, sulfate, nitrate, nitrite.
 3. The method ofclaim 1, wherein said acid gas scrubbing solvent includes an amine. 4.The method of claim 1, wherein said acid gas scrubbing solvent includesany mixture of a primary amine, secondary amine, or a tertiary amine. 5.The method of claim 1, wherein said acid gas scrubbing solvent includesa material selected from a group consisting of monoethanolamine (MEA),1-amino-2-propanol (1A2P), 3-amino-1-propanol, 2-amino-1-propanol,2-amino-1-butanol, 1-amino-2-butanol, 3-amino-2-butanol,2-(alkylamino)ethanonol (MAE), diglycolamine, morpholine, piperazine(PZ), 1-methylpiperazine (NMP), 2-methylpiperazine, hydroxypiperadine,hydroxyalkylpiperazine, 2-piperidineethanol, N-aminoethylpierazine(AEP), aminopropylmorpholine, 4-aminopiperidine, 3-aminopiperidine,2-amino-piperidine, diethanolamine, 2-amino-2-methyl-1-propanol (AMP),diethanolamine (DEA), diisopropanolamine (DIPA), glycine, alanine,β-alanine, sarcosine, isopropanolamine, benzylamine,methyldiethanolamine (MDEA), triethanolamine (TEA), alkali carbonate,N,N,-dialkylethanolamine, N,N,N′,N′-tetraalkyl-1,8-naphthalenediamine,N,N,-dialkylbenzylamine, 1,4-dialkylpiperazine,N,N,N′,N′-tetraalkyl-1,6-hexanediamine,N,N,N′,N′-tetraalkyl-1,5-pentanediamine,N,N,N′,N′-tetraalkyl-1,4-butanediamine,N,N,N′,N′-tetraalkyl-1,3-propanediamine,N,N,N′,N′-tetraalkyl-1,2-ethanediamine,N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine,N,N,N′,N′,N″-pentaalkyldiethylenetriamine,N,N,N′,N′,N″-pentaalkyldipropylaminetriamine,N,N,-dialkylcyclohexylamine, N,N,N′,N′-tetraalkylbis(aminoethyl)ether,N,N,-dimethyl-2(2-aminoethoxy)ethanol, where alkyl represents anymethyl, ethyl, propyl, butyl isomer, and mixtures thereof.
 6. The methodof claim 1, wherein said catalyst compound is provided at aconcentration of between about 0.05 mM and about 100 mM.
 7. The methodof claim 1, wherein said catalyst compound has a chemical formula:


8. The method of claim 1, wherein said catalyst compound has a chemicalformula:


9. The method of claim 1, wherein said catalyst compound has a chemicalformula:


10. The method of claim 1, wherein said catalyst compound has a chemicalformula:


11. The method of claim 1, wherein said catalyst compound has a chemicalformula:


12. The method of claim 1, wherein said catalyst compound has a chemicalformula:


13. The method of claim 1, wherein said catalyst compound has a chemicalformula:


14. The method of claim 1, wherein said catalyst compound has a chemicalformula:


15. A method of increasing overall mass transfer rate of acid gasscrubbing solvents, comprising: adding a catalyst compound to a fluidstream including an acid gas and an acid gas scrubbing solvent, saidcatalyst compound having a chemical formula:

where: (b) M is any group VII B through XII B element; (b) x=neutralsigma donor or monovalent anion; (c)

where R₁=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl, Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₂=H, any alkyl, RCOOH (R=alkylranging from 0-10 carbons); OligoPEG, phosphate, ROH (R=alkyl rangingfrom 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃;NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₃=H, anyalkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG, phosphate,ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeatunits); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃,[CH₂Q]⁺[A]⁻ R₄=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₅=H, any alkyl, RCOOH (R=alkylranging from 0-10 carbons); OligoPEG, phosphate, ROH (R=alkyl rangingfrom 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃;NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₆=H, anyalkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG, phosphate,ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeatunits); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃,[CH₂Q]⁺[A]⁻ R₇=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₈=H, any alkyl, RCOOH (R=alkylranging from 0-10 carbons); OligoPEG, phosphate, ROH (R=alkyl rangingfrom 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃;NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻; and[CH₂Q]⁺[A]⁻=

where A=monovalent anion: Cl, Br, I, F, PF₆, BF₄, acetate,trifluoroacetate, ClO₄, NO₃, and Q=monovalent cation: PR₃, R=alkyl,cyclic alkyl, Aryl, O-alkyl, O-Aryl NR₃, R=alkyl, cyclic alkyl,N-heterocyclic ring, imidazole (d)

where E₁=N, P, S, B E₂=N, P, S, O, B n=1-10.
 16. The method of claim 15,wherein said neutral sigma donor or monovalent anion is selected from agroup consisting of H₂O, Cl, Br, F, I, acetate, triflate, perchlorate,nitro, pyridine, ethanol, methanol, tetrahydrofuran, dimethylsulfoxide,carbonate, bicarbonate, sulfate, nitrate, nitrite.
 17. The method ofclaim 15, wherein said acid gas scrubbing solvent includes an amine. 18.The method of claim 15, wherein said acid gas scrubbing solvent includesa mixture of a primary amine, secondary amine, or a tertiary amine. 19.The method of claim 15, wherein said acid gas scrubbing solvent includesa material selected from a group consisting of monoethanolamine (MEA),1-amino-2-propanol (1A2P), 3-amino-1-propanol, 2-amino-1-propanol,2-amino-1-butanol, 1-amino-2-butanol, 3-amino-2-butanol,2-(alkylamino)ethanol (MAE), diglycolamine, morpholine, piperazine (PZ),1-methylpiperazine (NMP), 2-methylpiperazine, hydroxypiperadine,hydroxyalkylpiperazine, 2-piperidineethanol, N-aminoethylpierazine(AEP), aminopropylmorpholine, 4-aminopiperidine, 3-aminopiperidine,2-amino-piperidine, diethanolamine, 2-amino-2-methyl-1-propanol (AMP),diethanolamine (DEA), diisopropanolamine (DIPA), glycine, alanine,β-alanine, sarcosine, isopropanolamine, benzylamine,methyldiethanolamine (MDEA), triethanolamine (TEA), alkali carbonate,N,N,-dialkylethanolamine, N,N,N′,N′-tetraalkyl-1,8-naphthalenediamine,N,N,-dialkylbenzylamine, 1,4-dialkylpiperazine,N,N,N′,N′-tetraalkyl-1,6-hexanediamine,N,N,N′,N′-tetraalkyl-1,5-pentanediamine,N,N,N′,N′-tetraalkyl-1,4-butanediamine,N,N,N′,N′-tetraalkyl-1,3-propanediamine,N,N,N′,N′-tetraalkyl-1,2-ethanediamine,N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine,N,N,N′,N′,N″-pentaalkyldiethylenetriamine,N,N,N′,N′,N″-pentaalkyldipropylaminetriamine,N,N,-dialkylcyclohexylamine, N,N,N′,N′-tetraalkylbis(aminoethyl)ether,N,N,-dimethyl-2(2-aminoethoxy)ethanol, where alkyl represents anymethyl, ethyl, propyl, butyl isomer, and mixtures thereof.
 20. Themethod of claim 15, wherein said catalyst compound is provided at aconcentration of between about 0.05 mM and about 100 mM.
 21. The methodof claim 11, wherein said catalyst compound has a chemical formula:


22. The method of claim 11, wherein said catalyst compound has achemical formula:


23. A method of increasing overall mass transfer rate of acid gasscrubbing solvents, comprising: adding a catalyst compound to a fluidstream including an acid gas and an acid gas scrubbing solvent, saidcatalyst compound having a chemical formula:

where: (a) M is any group VII B through XII B element; (b) x=neutralsigma donor or monovalent anion; and (c)

R₁=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]+[A]-; and [CH₂Q]+[A]-=

where A=monovalent anion: Cl, Br, I, F, PF₆, BF₄, acetate,trifluoroacetate, ClO₄, NO₃, and Q=monovalent cation: PR₃, R=alkyl,cyclic alkyl, Aryl, O-alkyl, O-Aryl NR₃, R=alkyl, cyclic alkyl,N-heterocyclic ring, imidazole R₂=CE; where C=any alkyl, cyclic alkyl,aryl, and E=OH, NH₂, NR₃, R=alkyl, cyclic alkyl, N-heterocyclic ring,imidazole, morpholine.
 24. The method of claim 23, wherein said neutralsigma donor or monovalent anion is selected from a group consisting ofH₂O, Cl, Br F, I, acetate, triflate, perchlorate, nitro, pyridine,ethanol, methanol, tetrahydrofuran, dimethylsulfoxide, carbonate,bicarbonate, sulfate, nitrate, nitrite.
 25. The method of claim 23,wherein said acid gas scrubbing solvent includes an amine.
 26. Themethod of claim 23, wherein said acid gas scrubbing solvent includes amixture of a primary amine, secondary amine, or a tertiary amine. 27.The method of claim 23, wherein said acid gas scrubbing solvent includesa material selected from a group consisting of monoethanolamine (MEA),1-amino-2-propanol (1A2P), 3-amino-1-propanol, 2-amino-1-propanol,2-amino-1-butanol, 1-amino-2-butanol, 3-amino-2-butanol,2-(alkylamino)ethanonol (MAE), diglycolamine, morpholine, piperazine(PZ), 1-methylpiperazine (NMP), 2-methylpiperazine, hydroxypiperadine,hydroxyalkylpiperazine, 2-piperidineethanol, N-aminoethylpierazine(AEP), aminopropylmorpholine, 4-aminopiperidine, 3-aminopiperidine,2-amino-piperidine, diethanolamine, 2-amino-2-methyl-1-propanol (AMP),diethanolamine (DEA), diisopropanolamine (DIPA), glycine, alanine,β-alanine, sarcosine, isopropanolamine, benzylamine,methyldiethanolamine (MDEA), triethanolamine (TEA), alkali carbonate,N,N,-dialkylethanolamine, N,N,N′,N′-tetraalkyl-1,8-naphthalenediamine,N,N,-dialkylbenzylamine, 1,4-dialkylpiperazine,N,N,N′,N′-tetraalkyl-1,6-hexanediamine,N,N,N′,N′-tetraalkyl-1,5-pentanediamine,N,N,N′,N′-tetraalkyl-1,4-butanediamine,N,N,N′,N′-tetraalkyl-1,3-propanediamine,N,N,N′,N′-tetraalkyl-1,2-ethanediamine,N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine,N,N,N′,N′,N″-pentaalkyldiethylenetriamine,N,N,N′,N′,N″-pentaalkyldipropylaminetriamine,N,N,-dialkylcyclohexylamine, N,N,N′,N′-tetraalkylbis(aminoethyl)ether,N,N,-dimethyl-2(2-aminoethoxy)ethanol, where alkyl represents anymethyl, ethyl, propyl, butyl isomer, and mixtures thereof.
 28. Themethod of claim 23, wherein said catalyst compound is provided at aconcentration of between about 0.05 mM and about 100 mM.
 29. A compoundhaving a chemical formula:

where: (a) M is any group VII B through XII B element; (b) x=neutralsigma donor or monovalent anion; (c)

where R₁=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl, Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₂=H, any alkyl, RCOOH (R=alkylranging from 0-10 carbons); OligoPEG, phosphate, ROH (R=alkyl rangingfrom 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃;NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₃=H, anyalkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG, phosphate,ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeatunits); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃,[CH₂Q]⁺[A]⁻ R₄=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₅=H, any alkyl, RCOOH (R=alkylranging from 0-10 carbons); OligoPEG, phosphate, ROH (R=alkyl rangingfrom 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃;NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₆=H, anyalkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG, phosphate,ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeatunits); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃,[CH₂Q]⁺[A]⁻ R₇=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₈=H, any alkyl, RCOOH (R=alkylranging from 0-10 carbons); OligoPEG, phosphate, ROH (R=alkyl rangingfrom 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃;NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻; and[CH₂Q]⁺[A]⁻=

where A=monovalent anion: Cl, Br, I, F, PF₆, BF₄, acetate,trifluoroacetate, ClO₄, NO₃, and Q=monovalent cation: PR₃, R=alkyl,cyclic alkyl, Aryl, O-alkyl, O-Aryl NR₃, R=alkyl, cyclic alkyl,N-heterocyclic ring, imidazole; and (d)

where E₁=N, P, S, B E₂=N, P, S, 0, B n=1-10.
 30. A compound having achemical formula:

where: M is any group VII B through XII B element; (b) x=neutral sigmadonor or monovalent anion; (c)

where R₁=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl, Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₂=H, any alkyl, RCOOH (R=alkylranging from 0-10 carbons); OligoPEG, phosphate, ROH (R=alkyl rangingfrom 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃;NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₃=H, anyalkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG, phosphate,ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeatunits); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃,[CH₂Q]⁺[A]⁻ R₄=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₅=H, any alkyl, RCOOH (R=alkylranging from 0-10 carbons); OligoPEG, phosphate, ROH (R=alkyl rangingfrom 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃;NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₆=H, anyalkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG, phosphate,ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeatunits); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃,[CH₂Q]⁺[A]⁻ R₇=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons);OligoPEG, phosphate, ROH (R=alkyl ranging from 0-5 carbons),—[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃; NO₂; amine, amide,carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻ R₈=H, any alkyl, RCOOH (R=alkylranging from 0-10 carbons); OligoPEG, phosphate, ROH (R=alkyl rangingfrom 0-5 carbons), —[OCH₂CH₂]-m (m=number of repeat units); OH; SO₃;NO₂; amine, amide, carbonyl Cl, Br, I, F, BH₃, [CH₂Q]⁺[A]⁻; and[CH₂Q]⁺[A]⁻=

where A=monovalent anion: Cl, Br, I, F, PF₆, BF₄, acetate,trifluoroacetate, ClO₄, NO₃, and Q=monovalent cation: PR₃, R=alkyl,cyclic alkyl, Aryl, O-alkyl, O-Aryl NR₃, R=alkyl, cyclic alkyl,N-heterocyclic ring, imidazole (d)

where E₁=N, P, S, B E₂=N, P, S, 0, B n=1-10.
 31. A compound having achemical formula:

where: (a) M is any group VII B through XII B element; (b) x=neutralsigma donor or monovalent anion; and (c)

R₁=H, any alkyl, RCOOH (R=alkyl ranging from 0-10 carbons); OligoPEG,phosphate, ROH (R=alkyl ranging from 0-5 carbons), —[OCH₂CH₂]-m(m=number of repeat units); OH; SO₃; NO₂; amine, amide, carbonyl Cl, Br,I, F, BH₃, [CH₂Q]+[A]-; and [CH₂Q]+[A]-=

where A=monovalent anion: Cl, Br, I, F, PF₆, BF₄, acetate,trifluoroacetate, ClO₄, NO₃, and Q=monovalent cation: PR₃, R=alkyl,cyclic alkyl, Aryl, O-alkyl, O-Aryl NR₃, R=alkyl, cyclic alkyl,N-heterocyclic ring, imidazole R₂=CE; where C=any alkyl, cyclic alkyl,aryl, and E=OH, NH₂, NR₃, R=alkyl, cyclic alkyl, N-heterocyclic ring,imidazole, morpholine.